I'm currently on Sierra 10.12.1 and my hardware is:
i5 3570K
z77-DS3H
EVGA GTX 970 SSC
I've tried 14.2, 13.2, 12.2, and MacPro 3.1 and no luck with any of those.
I installed the Nvidia web drivers, checked off NvidiaWeb in Clover configurator, EmuVariableUefi, and rebooted with the graphics...